Which mobile extractor - L, M, H? And for what materials?

simon, I concur with what my 2 pennies writes.

Most name brand vacuums come with the same filters across the range.
You can have an L class vac with the same filtration as an H class vacuum.
The vacuum will still be classified as an L class because it won't have the airflow measuring alert.
It will however provide the same level of filtration.

M & H class vacuums will often come with some other extra niceties like an antistatic hose instead of a regular hose, a sealing cap for the port when transporting the vacuum, etc.


The mafell S25 and S50 vacs are the previous generation of Starmix iPulse. The S35 is the newest generation.
I believe in the iPulse range the L & M class come with the same filters, the H class has a different one.

So to sum things up. Some countries like Britain require that you have an M class vacuum for site use, other don't.
Unless an audible airflow signal is important to you, you're better off buying an L-class vacuum.

(just as an FYI in combination with certain power tools the audible warning of an M class can sometimes be very annoying as it goes off all the time, even thoug there isn't really a problem. The alarm can go off due to the design of the power tool.)

My view on it is quite simple if the job requires an H rated then leave it for someone else to deal with

gnehehe

The nano coating on the filters is supposedly there to facilitate the filter cleaning. Kind of sounds like marketing to me though. It has no impact on the filtration level of the filters.
And correct, what isn't caught by the filters passes through the unit.

Simon where are you from? If you're from Europe I'd recommend you buy the Starmix iPulse ARM-1635 EWA



If you're from the States I'd recommend you buy a Metabo ASR 35 ACP




There is no need to over analyse this stuff. You'll be hard pressed to find a better dust extractor than this! 

Perhaps it could be explained more succinctly:  why the necessity for automatic filter cleaning?  Surely this feature is predicated upon the relative "harmfulness" of the dusts being inhaled.  I can understand the necessity for this feature in hazardous dusts like asbestos fibre, the silicates released in concrete cutting & grinding operations and maybe to a lesser extent gypsum dusts from plaster finishing. Many extractors have had auto filter cleaning for years:  I can recall a contractor's Karcher vac thumping its way to clean filters every 10 seconds or so from about 20 years +/- ago.  In this particular case whilst cleaning up sheet asbestos dusts from a major school hall renovation.

The extractors I've owned, a Festo & a Festool each had fully enclosed & closeable dustbags, of both the disposable & reuseable varieties, pre filters, & pleated synthetic filters.  The key here is the quality of the dustbag fabric & fabrication, surely.  I'm lead to believe that the "hazardous dust/s" bags that are used these days aren't even enclosed, but merely expensive, open-topped plastic bags that are in effect folded over & sandwiched between the motor and dust hopper housings, with a rather dubious seal between.

Is this correct?  If so, then I can understand the necessity for having the very best filtration possible:  the net effect of such an arrangement is in essence to actually have no dustbag in place at all.  There's no cyclonic element to the separation of air & airbourne dust & aerosols other than the rather crude force of gravity and the main filter itself.  In these circumstances it would be essential to have the very best filtration possible, together with these auto filter thumping arrangements, but I cannot for the life of me see why this essentially unbagged dust need to be caking the filter at all in such large quantities.  The simple addition of an effective dustbag would surely be superior to having nothing at all but an open topped impervious polythene bag to catch the heaviest dusts and that which is dislodged by the filter agitator/s.

It just seems counter-intuitive to me.  You stop the vac, plug the outlet, crack it open, in the process dislodging highly concentrated residual fine hazardous dusts in the process, shake the bag down before twisting & tying it off, remove the bag and only then plug the inlet before disposal.  As polyester is impervious, there's no other leakage at all - I get that - but in the process of removing the bag from the vac you're exposing yourself to pretty high concentrations of the very finest & most easily aerosolised hazardous material that you were trying to avoid.

Am I missing something here?  Is there some sort of magic step in the process that I've missed that avoids clouding the air with highly concentrated dust?  What about the presumably abysmally short working lifespan of these highly contaminated filters?  How are these to be safely removed & disposed?  Surely an effective, enclosed & sealable disposable dustbag would be an advantageous extra barrier in the chain of filtration, lessening the operator's exposure to these hazardous dusts.  I full realise that in comparison to polyethylene bags that said dustbags are of necessity porous, but surely they can be effectively rebagged in plastic & sealed immediately following removal.  In Oz anyway, hazardous materials such as asbestos require triple impervious bagging with individual sealing.

I've never vacuumed up any asbestos myself.  It's not something I've even contemplated, nor am ever likely to.  I have, however, worked pretty intensively with cement and concrete.  Forming, pouring, finishing, cutting, grinding, chiselling & chasing.  The 2 vacs that I've used are, it must be said, unrated & therefore immediately to be considered inadequate to the task, however I've always used disposable bags, both paper & polyester fleece, attached to my cutting & grinding tools, and have found them (superficially anyway) to be adequate to the task.  There's little residue apparent on the vac's filters.  The bags, however, are subject to premature clogging of their pores, which limits their use to a small fraction of their overall capacity.  So they get changed much more frequently.

I understand that this is less than ideal in terms of operator protection or to decrease the incidence of airbourne dusts, but it was all that was available in the past.  I intend to buy a new extractor in the coming week (an M-class semi-auto Metabo ASR 50 SC) to use in all my operations, including concrete & stone processing.  I simply cannot for the life of me understand how using an open-topped bag with a totally exposed filter could be better than a fully enclosed, sealable but porous bag that filters almost all the dust residues from the main (M-class) filter.  Generally, my filters are kept pretty clean, whereas a filter that has total unimpeded exposure to both fine & course dusts must have a severely limited lifetime.

How often must one replace & dispose of these highly contaminated filters?  Weekly?  Daily?  Hourly?  My filters in the old Festo need replacing once every 6 months to a year, & the longlife filters in the CT22 only every couple of years or so.  Personally I find the whole concept of exposing expensive filters directly to the incoming contaminated airstream seemingly some sort of a scam to induce the operator to spend up big on otherwise unneccessary filter replacement.

As an additional aside, any sort of filter cleaning; manual, semi-auto or automatic, not only becomes pretty irrelevant when using enclosed dustbags (where does the dislodged dust go?) but would actually be counter-productive to the process of keeping those nasty silicates safely enclosed.  Surely in a bagged vac, any sort of auto filter cleaning would actually be rather hazardous:  those fines would be better off in the filter (where they surely belong & can be safely disposed of) rather than floating around unimpeded in the vac's interior?

For these reasons in particular, I suspect that these newer Starmix 35l M & H class extractors actually seem a retrograde step in terms of operator safety.

Simon the Bosch Gas L 35 and M35 have variable suction , for sanding etc . Excellent suction and flow more suction than the starmix . It has 1800w power tool out put and a 5m long hose , really good vacs.
On board storage could be better tbh but you could click a Bosch l box on top and put all the cleaning tools and bits in there , the top of the vac is designed to do this.